Malleable fittings Selection Guide - Jianzhi Pipe Fittings

What are the standards and technical parameters that need to be paid attention.

when selecting malleable pipe fittings—Take 4 way cross pipe fitting as an example.

You will get efficient and thoughtful service from JIANZHI.

As an indispensable industrial product in human modern life, malleable pipe fittings are already a highly standardized modern industrial product. These standards are summarized and perfected in people’s continuous engineering practice, and more and more standards have been determined to ensure and improve the independence (commercialization), compatibility, interoperability, repeatability safety and of quality malleable products.

A small pipe fitting can be accurately described by many standard parameters. Only when both buyers and sellers clearly and accurately understand the meaning of these standard parameters can they communicate efficiently and smoothly, so as to avoid ambiguity. Close deals quickly. Now let us take the 4 way cross pipe fitting of China Jianzhi brand as an example to explain some technical parameters and precautions about malleable pipe fittings. The following is a link to the website of this product, you can see some technical parameters on the page: 4 Way Pipe Fitting Equal Cross

National standard number of pipe fittings

The above table lists the standard numbers of pipe fitting products in major countries in the world. The national standards promulgated by each country specify the standards that related products should meet in detail. You can query the standards of pipe fitting products in related countries through the number.

This is also the fastest and most intuitive way to understand a country’s requirements for related industries. The national standard for malleable iron pipe fittings in China is GB/T-, and the material standard for malleable iron is GB/T-. Jianzhi Group is the main drafting unit of these two standards and plays a key role in the revision of the standards. Below we will explain some key values in conjunction with China’s national standards.

Relevant standards for malleable iron materials

Malleable cast iron is cast iron with a certain chemical composition into a white blank and then annealed. It has high strength, plasticity and impact toughness, and can partially replace carbon steel. The grade of malleable cast iron is indicated by the percentage of the minimum tensile strength value (MPa) and the minimum elongation after fracture, followed by “KTH” (the Chinese phonetic prefix of black-heart malleable iron) or “KTZ” (the Chinese phonetic prefix of pearlitic malleable iron).

For example, the grade KTH 350—10 represents a black-core malleable iron with a minimum tensile strength of 350 MPa and a minimum elongation after fracture of 10%, namely ferritic malleable cast iron; KTZ 650—02 represents a minimum tensile strength of 650 MPa and a minimum elongation after fracture of 650 MPa. Pearlitic malleable iron with a rate of 2%. The material used for the Jianzhi brand 4way cross pipe fitting in the picture below is the black-heart malleable cast iron with the grade of KTH 350-10.

Standards for threads

Threads are divided into two types: sealed and non-sealed. Different countries have different regulations for these two types of threads. However, the common threads mainly include the following: NPT, PT, G, etc.

1. NPT is the abbreviation of National (American) Pipe Thread, which belongs to the American standard 60-degree tapered pipe thread, which is mostly used in North America.
2. PT is the abbreviation of Pipe Thread, which is a 55-degree sealed conical pipe thread, which belongs to the Wyeth thread family, and is mostly used in Europe and the Commonwealth of Nations.
3. G is a 55degree unsealed pipe thread, which belongs to the Whitworth thread family. Marked as G stands for cylindrical thread.

Moreover, there are three differences between the metric and Anglo-American thread representation methods:

1. Metric threads are expressed by pitch, and American and British threads are expressed by the number of threads per inch.
2. Metric threads are 60-degree equilateral threads, inch threads are isosceles 55-degree threads, and American threads are isosceles 60-degree threads.
3. Use metric units (such as mm) for metric threads, and imperial units (such as inches) for American and British threads.

China used the metric thread standard for the malleable steel pipe fittings at the earliest stage, and gradually adopted the inch thread standard in the later development. Therefore, the national standard thread of Jianzhi can be used in common with the British standard thread.

It is worth noting that different countries also have different standards for the thread of malleable steel pipe fittings. This must be communicated well before the transaction. Thread selection is very important for the smooth installation of pipe fittings.

Description of Malleable Pipe Fittings

There are many values involved in the description of malleable iron pipe fittings, mainly including size, maximum working pressure, maximum working temperature, elongation and other values.

Taking Jianzhi brand 4way cross pipe fitting as an example, the following figure is the size comparison table:

It is worth noting that in and mm are not directly converted, and they need to be compared strictly according to the values in the above table.

As shown in the figure above, most of the values describing malleable pipe fittings can be easily known by their literal meaning. When you put your needs to the seller, you should pay attention to the following two points:

1. Make it clear what your needs are. For malleable iron pipe fittings, what standard should the seller’s products meet?
2. Make your requirements as comprehensive as possible. There are many standard parameters involved in malleable iron pipe fittings. We must communicate with the seller’s salesman in as much detail as possible, and do not miss any of them, so as to avoid unnecessary losses.

The Ultimate FAQ Guide Of Galvanized Pipe Couplings

This guide answers all the questions you have about galvanized pipe couplings. If you have been looking for information about galvanized steel merchant couplings, look no further.

For more How to choose a suitable Chinese galvanized pipe fittings supplier?information, please contact us. We will provide professional answers.

You will find the most direct, yet detailed answers to basic questions, you often ask about galvanized steel full merchant couplings and half merchant couplings.

Without further ado, here we go:

• What Are Galvanized Pipe Couplings?

Galvanized pipe couplings are made of high-quality galvanized carbon steel pipes. Galvanized couplings are electroplated zinc or hot-dipped zinc, and galvanizing can increase the corrosion resistance of the steel pipe coupling and prolong the service life.

Galvanized pipe couplings are mainly used for the extension of water supply pipes in residential and commercial buildings.

• Key Features And Benefits

1. Anti-corrosion: The galvanized coating supplies reliable protection for coupling by avoiding water and oxygen contact directly with metal coupling to decrease rust and corrosion. That makes galvanized coupling very suitable when used in water systems.

2. Durable: The galvanized coupling is fit for work in multiple kinds of workplaces and can bear high pressure. Their high strength and durability contribute to extended use lifelong.

3. Easy to install: The galvanized nipples are designed female threaded usually, easy to install, and without more tools, you can install or remove them toilless at any time.

4. Low cost: Because of their durability and high quality, the maintenance charges are low during use. In the long run, this is reasonable and money-saving.

• What Are Galvanized Merchant Couplings?

There are so many different types of couplings available and each one has its own specific application. For example, when connecting drop pipes in a well, you may consider using merchant couplings to connect them.

SANVO galvanized merchant couplings are threaded and made of galvanized carbon steel pipes, including standard galvanized full merchant couplings, standard galvanized half merchant couplings, extra heavy galvanized full merchant couplings, extra heavy galvanized half merchant couplings, etc.

• Galvanized Merchant Coupling Thread Standards

Merchant couplings are manufactured per ASTM A865 and are intended for use on steel pipe joints by ANSI B1.20.1. Sizes 1⁄8" NPS through 2" NPS are straight-tapped. Sizes 2 1⁄2" NPS and larger are always taper-tapped.

The difference between straight thread and tapered thread

1. First, it comes down to cost. Tapered threads cost more to manufacture while straight threads cost less to produce.

2. Second, tapered threads seal better. They seal better because the threads get tighter the further down the coupling, while straight threads stay the same width throughout.

All merchant couplings are chamfered before they are threaded. This means that before the threading is done, a chamfer is created. It can be tricky to tell where the threads start on the chamfer, but it helps start threading the pipe into the coupling.

• Where To Buy/Purchase Galvanized Steel Merchant Couplings?

SANVO is a good stainless and carbon steel coupling supplier, manufacturer, wholesaler, exporter, factory, and company in China, and supplies standard and extra heavy galvanized steel full merchant couplings, half merchant coupling, and API line pipe couplings, etc. 

Our galvanized steel merchant couplings can be customized according to drawings, samples, or special requirements of customers, and send samples for free. So, you can choose Hebei Sanvo Pipes And Fittings Co., Ltd. to buy/purchase galvanized steel merchant couplings.